Coronary imaging of cardiac allograft vasculopathy predicts current and future deterioration of left ventricular function in patients with orthotopic heart transplantation.

BACKGROUND: Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) improve sensitivity of cardiac allograft vasculopathy (CAV) detection compared to invasive coronary angiography (ICA), but their ability to predict clinical events is unknown. We determined whether severe CAV detected with ICA, IVUS, or OCT correlates with graft function. METHODS: Comparison of specific vessel parameters between IVUS and OCT on 20 patients attending for angiography 12-24 months post-orthotopic heart transplant. Serial left ventricular ejection fraction (EF) was recorded prospectively. RESULTS: Analyzing 55 coronary arteries, OCT and IVUS correlated well for vessel CAV characteristics. A mean intimal thickness (MIT)OCT  > .25 mm had a sensitivity of 86.7% and specificity of 74.3% at detecting Stanford grade 4 CAV. Those with angiographically evident CAV had significant reduction in graft EF over 7.3 years follow-up (median ΔEF -2% vs +1.5%, P = .03). Patients with MITOCT  > .25 mm in at least one vessel had a lower median EF at time of surveillance (57% vs 62%, P = .014). Two MACEs were noted. CONCLUSION: Imaging with OCT correlates well with IVUS for CAV detection. Combined angiography and OCT to screen for CAV within 12-24 months of transplant predicts concurrent and future deterioration in graft function.

Management of arrhythmias in pulmonary hypertension.

BACKGROUND: Pulmonary hypertension (PH) is a potentially devastating clinical condition with a poor long-term prognosis. Cardiac arrhythmias are frequent in PH, and pulmonary hypertensives are particularly susceptible to the adverse haemodynamic effects of heart rhythm disorders. However, arrhythmia management in PH patients can be more challenging than in the general population due to the particular physiological idiosyncrasies associated with the condition. Here, we summarise and appraise the data pertaining to multimodality treatment of cardiac arrhythmias in PH to help refine the management strategy for this vulnerable patient group. RESULTS: The majority of our understanding of the safety and effectiveness of different arrhythmia treatments in PH is based on observational and retrospective data. Rhythm control is the overall goal, and for atrial and ventricular tachyarrhythmias, referral for catheter ablation, ideally using electroanatomical mapping technology in specialist centres, is the preferable means of achieving this. Contradictory viewpoints are expounded regarding the safety of beta blocker use in PH, though in three small prospective clinical trials and at least six animal models they appear to be well-tolerated. Nevertheless, amiodarone remains the preferred pharmacological treatment. Direct current cardioversion can be carried out effectively to terminate tachyarrhythmias in both the emergency and elective setting, though mechanistic studies demonstrate a higher recurrence rate in PH patients. Individual reports and series suggest that device implantation may be technically challenging and associated with a higher complication rate due to anatomical distortion and chamber enlargement. Modulation of sympathetic input to the heart appears to reduce arrhythmia vulnerability in canine models of PH, and its clinical application in humans is a worthwhile area of further study. CONCLUSION: Prompt restoration of sinus rhythm improves outcomes in PH, and at present, the most reliable and safest strategy for long-term rhythm control is amiodarone and, where possible, ablation. Reinforcement of the evidence base with randomised prospective trials is necessary. This would be particularly beneficial to clarify the role of atrial fibrillation ablation and the safety and efficacy of beta-blockers. In addition, a more comprehensive assessment of the vulnerability of PH patients to potentially fatal brady- and ventricular tachyarrhythmias may help guide recommendations for provision of primary prevention device therapy.